In the 12th Century, construction of a bell tower behind the Pisa Cathedral began. Due to it being built upon soft soil with only 3m of foundations, the tower began to subside on one side during the construction phase. Despite this, the bell tower was eventually completed nearly 200 years after starting. However, each year the tower increased its tilt by 1mm, until in 2001 it got to the point of no return. Had work not been carried out to correct the foundations, the tower would have collapsed under the immense pressure being exerted on it. Although it has now been corrected (to an extent), engineers believe that in a couple of centuries, it will likely be at a point where correction will need to be made again.

Isn’t this interesting? Due to building upon poor foundations, the building will never last without regular intervention…